Micron ships first Hybrid Memory Cubes

Micron's first Hybrid Memory Cube devices are rolling off the production lines, offering 2GB of DRAM in a four-layer stack with a claimed 70 per cent lower power draw than planar memory and a whopping 160GB/s transfer rate.

Micron has officially started shipping its first Hybrid Memory Cube (HMC) devices, using through-silicon vias (TSVs) to stack four 4Gb DRAM dies into a single 2GB cube.

The company has now delivered on its promise, producing the first commercial HMC devices and offering engineering samples to its customers immediately, ahead of mass production.

The engineering sample devices offer 2GB of storage with a claimed 160GB/s transfer rate in a compact footprint with a 70 per cent reduced power draw per bit compared to traditional planar memory layouts. The HMC works by allowing chips underneath the stack to communicate with those on top, and vice-versa, using electrical conduits known as vias which pass through the silicon of the chip itself - hence 'through-silicon vias.'

'System designers are looking for new memory system designs to support increased demand for bandwidth, density, and power efficiency,' claimed Micron's Brian Shirley, vice president of the DRAM Solutions group, at the announcement. 'HMC represents the new standard in memory performance; it's the breakthrough our customers have been waiting for.'

In addition to the 2GB engineering samples available now, Micron has promised to produce 4GB versions in early 2014 ahead of volume production of both later that year. The company is so confident of the technology's success, in fact, that it claims it will take just three to five years for the first mainstream HMC-enabled consumer products to appear on shop shelves.

Originally Posted by Chicken76If volume production is to start next year, why is it going to take three to five years for the first consumer products equipped with HMC RAM to appear on shop shelves?

Because that's how long it takes to design a product. HMC modules are not pin- nor electrically-compatible with existing DRAM modules, so to integrate them into your product means buying some samples, building prototypes, testing the prototypes, building more prototypes, testing those, repeating until they work, creating your design, testing your design, certifying your design, buying bulk units, producing your design and finally releasing your design. To put it another way: why haven't we got DDR4 in our PCs yet? The standard was finalised in September 2012, which was the originally-scheduled release-to-market date.

The other point to bear in mind is consumer products: I reckon we'll be seeing the first products with HMC by the end of 2014, but they won't be aimed at the consumer; they'll be niche products aimed at very specific markets and produced in very limited numbers. Much like multi-core processors once were...

Originally Posted by Chicken76Another question: the sizes mentioned in the article are 2 and 4 gigabits or gigabytes per package?

Each HMC offers two gigabytes, made up of four layers of four-gigabit DRAM (4x4=16Gb, 16Gb/8=2GB.) The next step is the four gigabyte modules, although Micron hasn't stated whether these will be made by doubling up the layers (8x4=32Gb, 32Gb/8=4GB) or using higher-density layers (4x8=32Gb, 32GB/8=4GB.)

" using through-silicon vias (TSVs) to stack four 4Gb DRAM dies into a single 2GB cube." << Onto a single 2gb cube? Why not state the total capacity instead of saying "2gb". Last time I looked my 4 x mem modules came to 16gb = 4gb per module. Are they built on 2gb cubes too?

Originally Posted by Stanley Tweedle" using through-silicon vias (TSVs) to stack four 4Gb DRAM dies into a single 2GB cube." << Onto a single 2gb cube? Why not state the total capacity instead of saying "2gb". Last time I looked my 4 x mem modules came to 16gb = 4gb per module. Are they built on 2gb cubes too?

Take a look up-thread: I did state total capacity. A Gb is a gigabit, a GB is a gigabyte. There are eight gigabits in a gigabyte. The memory cube, as the article states, is made from four DRAM layers of 4Gb a piece; this makes for a cube of 16Gb capacity, or to use the more common measurement 2GB.

As for why the mixing of Gb and GB: the memory industry has always measured the chips themselves in Gb and the modules they make up in GB. That's just the way it works.

EDIT: Oh, and the 'gb' you talk about in your post? That's not a measurement of anything, I'm afraid. Case matters in this instance.

Originally Posted by Gareth HalfacreeEach HMC offers two gigabytes, made up of four layers of four-gigabit DRAM (4x4=16Gb, 16Gb/8=2GB.) The next step is the four gigabyte modules, although Micron hasn't stated whether these will be made by doubling up the layers (8x4=32Gb, 32Gb/8=4GB) or using higher-density layers (4x8=32Gb, 32GB/8=4GB.)

I see.
I wonder if these chips are going to be any bigger than current ones. I mean, they might be thicker, but are they going to need more PCB space also? With next year's 4GB packages, there could theoretically be 32 GB DIMMs with 8 (9 for ECC) HMC packages. That is, if they retain a comparable footprint.